Self-coupling device for drawout mounted electric apparatus

ABSTRACT

An electrically conducting and mechanically guiding selfcoupling device for connecting and disconnecting a terminal member of a removable electric apparatus, such as a circuit interrupter, to and from a stationary terminal member of a metal housing. The device comprises plug-in members for mechanical guiding and coaxial resilient contact means whereby the plug-in members position the terminal members in a manner preserving the contact means from mechanical stresses.

United States Patent [191 Henry et al. [4 1 June 5, 1973 [54] SELF-COUPLING DEVICE FOR [56] References Cited DRAWOUT MOUNTED ELECTRIC APPARATUS UNITED STATES PATENTS Inventors: Jean-Claude y, Grenoble; 2,476,071 7/1949 Spiro "200/168 Cesar Castem, 38 Montfleury; 3,041,573 6/1962 Offerman ..339/l86 T X Georges Henry, 38 St. Martin-le- Primary Examiner-Marvin A. Champ|on of France Assistant ExaminerWilliam F. Pate, ill [73] Assignee: Merlin Gerin, Societe Anonyme, Attorney-Stevens. Davis, Miller & Moshe! Grenoble, France 221 Filed: Sept. 8, 1971 [57] ABSTRACT An electrically conducting and mechanically guiding [21] Appl' self-coupling device for connecting and disconnecting a terminal member of a removable electric apparatus, [30] Foreign A lication Priority Dat such as a circuit interrupter, to and from a stationary terminal member of a metal housing. The device com- Sept. 17,1970 France prises p g members for mechanical and coaxial resilient contact means whereby the plug-in g. "339/64 339/65 members position the terminal members in a manner 53 Field of Search ..3 39/65, 64, 255 RT, 55,1121 the means fwm mechamcal 339/256 RT, 186 T 2 Claims, 2 Drawing Figures Patented June 5, 1973 {Snail-Shin? SELF-COUPLING DEVICE FOR DRAWOUT MOUNTED ELECTRIC APPARATUS in urban centers.

The circuit-interrupters are often of the compressed gas type and in a grounded metal housing or tank containing a more or less compressed dielectric gas. Genand has at its upper part a cover 16 flanged tightly onto the housing 10. Two lateral studs 18 and 20 in the vicinity of the ends of the cylinder 10 surround an input conductor 22 and an output conductor 24, respectively, which are supported concentrically by an insulating partition of frustoconical shape 26, preferably gas tight. The outer part of the conductors 22 and 24 is connected to the bus bars (not shown) of a metalclad installation or to an apparatus of such an installation, while the inner part bears a terminal member 25 which will be described in further'detail below with referally, the arc-extinguishing gas and the dielectric gas I are constituted by the same gas, such as sulfur hexafluoride, which circulates in closed cycle between the arc-extinguishing chambers of the circuit interrupter and the tank. The circuit interrupter is normally of the drawout mounted kind. That is, the circuit interrupter is removable as a whole from the stationary support means of the housing and withdrawable therefrom through an appropriate opening. Usually the heavy removable unit is securedby bolts to the housing and to the electrical terminals of the housing. The removal of the circuit interrupter involves loosening of the bolts at a place which is relatively inaccessible.

Known plug-in type connecting devices cannot be utilized for heavy high-voltage apparatus and are not adapted for precise positioning. Moreover, the electric contacts are unable to assume a mechanical guiding or supporting function because of the weight of the involved apparatus and the high stresses resulting therefrom.

It is an object of the invention to provide a selfcoupling electrical and mechanical connecting device of particularly simple construction permitting the mechanical guiding of the removable unit by the stationary unit during disconnecting and connecting movements and also in the connected position, independently of the action of the electric contact means which are preserved from the mechanical stresses inherent to mechanical guiding and. supporting.

By dissociating the mechanical and electrical functions of the self-coupling connecting device, each of the elements can be perfectly designed and adapted to its own function. Thus, the electric contacts are preserved from damage resulting from forces produced for example by electrodynamical forcesor mechanical vibrations. 1

Other objects and advantages of the invention will become evident from the following description of an embodiment of an invention shown in the accompaying drawings, in which:

FIG. 1 is a schematic elevation, partially in crosssection, of a circuit interrupter-in accordance with the invention;

FIG. 2 shows the connecting device of FIG. 1 on a larger scale, in cross-section.

In the figures, a vertical cylindrical metal housing or tank 10 rests by its lower'end 12 on abase 14 which receives, for instance, the;auxiliary control mechanisms and equipment. The housing 10 is at ground potential erence to FIG. 2.

Within the housing 10 there is accomodated an interrupting assembly designated generally by the numeral 28 and formed of two coaxial arc-extinguishing chambers 30 and 32, each containing separable contacts (not shown) which may be off-center with respect to the associated chamber and which are electrically connected in series. The chambers 30 and 32 contain a high-pressure arc-extinguishing and insulating fluid,

- such as sulfur hexafluoride (SP which exhausts into the housing 10 through appropriate orifices after triggering of the circuit and blasting of the arc drawn between the separating contacts. The control boxes 34 and 36 of the chambers 30 and 32 are partially overlapping, tie rods (not shown) connecting the latter together so as to constitute a single assembly capable of being withdrawn as a single unit from the tank 10 through the upper opening. Insulating supports 38 and 40 rigidly connected with the removable unit 28 are fastened to the bottom of the tank 10, for instance by bolts 41 accessible from the outside of the housing 10. The unit 28 has input and output terminals 42 and 44 connected electrically to the associated contacts of the chambers 30 and 32 and protruding laterally from the walls of the chambers 30 and 32, respectively. Each terminal 42, 44 is terminated by a plug-in element 46 which cooperates with the mating element 25 terminating the conductors 22 and 24 so as to establish an electrical and mechanical connection between the terminal members 46 and 25 which participate in the guiding and support of the unit 28.

With reference to FIG. 2, there will now be described one of the connecting devices, for instance between the terminal 42 and the conductor 22, the other device being identical. The terminal 42 is terminated by a plug member designated generally by the numeral 46 and which comprises an electrical contact stud 48 having a cylindrical outer contact surface which is terminated by a beveled surface 49 and is extended by a coaxial guide pin 50 with frustoconical tip 52. The pin 50 is fastened to the terminal 42, for instance by screwing a threaded end 54 opposite the tip 52 into a mating tapped recess in the terminal 42, the cross-section of the'finger 50 being less than that of the stud 48. The cylindrical portion of the pin 50 is surrounded by'an insulating sleeve 56 consisting of a material of low coefficient of friction held on the pin 50 by a collar 58 of the tip 52. The axial length of the sleeve 56 of the cylindrical part of the finger 50 extends beyond that of the stud 48 for reasons which will become more evident below.

The plug member 46 cooperates with a mating socket member, designated generally by the numeral 25 and fastened to the conductor 22, for instance by screwing a protuberance 60 of a body 62 into a tapped cavity of the conductor 22.

The body 62 has a cylindrical inner bore 64 corresponding to the outer section of the sleeve 56, and which is extended on both sides by a flared guide portion 66 and 68. The body 62 furthermore has an outer cylindrical contact surface 70 of a cross-section similar to that of the contact stud 48 which in engaged position of the plug member 46 in the socket 25 forms a prolongation of the stud 48. A plurality of contact fingers 72 are distributed around the body 62, a circumferential bias spring 74 holding one of the ends of the fingers 72 against and in contact with the contact surface 70. Each finger 72 has at its end a notch 76 in which there fits a collar 78 of a locking ring 80 fastened, for instance by screwing, on the body 62. The assembly consisting of contact surface 70 and fingers 72 constitutes a tulip-shaped contact clamp, well known per se, the free ends of the fingers 72 of which surround the stud 48 under the action of a second circumferential bias spring 81.

The self-coupling device formed of the plug member 46 and the socket member 25 is included, in engaged position, within a hood of conductive material consisting of two hemispherical parts 82 and 84 assembled by screws 86 and fastened to the conductor 22 by engage ment in a peripheral groove 88 of the latter. The hood 82, 84 is provided, opposite the contact clamp 72, with an opening 90 for the passage of the plug member 46.

The device in accordance with the invention operates in the following manner In order to effect the withdrawal of the unit 28 from the tank it is sufficient to raise the unit 28, of course after having removed the cover 16 and the connecting bolts 41, in a manner which does not form part of the present invention and which will therefore not be described, and after having disconnected the control and [or feed pipes (not shown). During the lifting of the unit 28, the plug members 46 of the terminals 42 and 44 are withdrawn from the mating socket members 25, interrupting the electrical and mechanical connection without manual intervention in this zones.

The engaging is effected by the reverse operation during which the frustoconical tips 52 first come into contact with the bodies 62, establishing the centering of the pins 50 which penetrate thereupon into the cylindrical part 64 of the socket members 25. Each stud 48 is then inserted between the contact fingers 72 which, after spreading by the inclined surface 49, come into contact with the studs 48, assuring the electrical connection. In plugged position, the current passes from the conductor 22 to the body 62 and via the contact fingers 72 and the stud 48 to the terminal 42. A rigid mechanical connection between the terminal 42 and the conductor 22 results from the insertion of the finger 50 into the body 62, whereby the sleeve 56 facilitates the sliding upon this insertion. The terminals42 and 44 are connected in identical manner tothe conductors 22 and 24 respectively, the electrical contact members being entirely freed of any mechanical stress which might affect their operation, in particular electrodynamic stresses due to the passage of the current in a loop shape.

In the case of a horizontal arrangement of the enclosure 10, the unit 28 can be entirely supported by the terminals 42 and 44 plugged on the conductors 22 and 24, a suitable connection preventing the pendulum movement on the pins 50.

What is claimed is 1. An electrically conducting and mechanically guiding self-coupling device for connecting and disconnecting a terminal member of the removable element of an enclosed drawout mounted electric apparatus to and from a stationary terminal member, comprising a. a socket member secured to one of said terminal members,

b. a plug member secured to the other terminal member and shaped for reception by said socket member in mechanical guiding relation,

c. said socket member and said plug member comprising each an external substantially cylindrical electric contact surface, and

d. resilient annular contact means carried by one of said terminal members in engagement with the corresponding contact surface and positioned to .engage the contact surface of the other terminal member after engagement of said socket member and said plug member during the coupling movement of said terminal members and to disengage said contact surface of said other terminal member before disengagement of said socket member and said plug member during the uncoupling movement of said terminal members, said socket member and said plug member positioning said terminal members independently of the action of said annular contact means on said contact surfaces.

2. A device as set forth in claim 1, wherein said plug member comprises a metallic cylindrical core member surrounded by a sleeve of insulating material insulating said core member electrically from said socket member in engaged position of said socket member and said plug member. 

1. An electrically conducting and mechanically guiding selfcoupling device for connecting and disconnecting a terminal member of the removable element of an enclosed drawout mounted electric apparatus to and from a stationary terminal member, comprising : a. a socket member secured to one of said terminal members, b. a plug member secured to the other terminal member and shaped for reception by said socket member in mechanical guiding relation, c. said socket member and said plug member comprising each an external substantially cylindrical electric contact surface, and d. resilient annular contact means carried by one of said terminal members in engagement with the corresponding contact surface and positioned to engage the contact surface of the other terminal member after engagement of said socket member and said plug member during the coupling movement of said terminal members and to disengage said contact surface of said other terminal member before disengagement of said socket member and said plug member during the uncoupling movement of said terminal members, said socket member and said plug member positioning said terminal members independently of the action of said annular contact means on said contact surfaces.
 2. A device as set forth in claim 1, wherein said plug member comprises a metallic cylindrical core member surrounded by a sleeve of insulating material insulating said core member electrically from said socket member in engaged position of said socket member and said plug member. 